Yesterday, phys.org posted a story titled, “No Big Bang? Quantum equation predicts universe has no beginning.” Coauthors Ahmed Farag Ali and Saurya Das, “have shown in a paper published in Physics Letters B that the Big Bang singularity can be resolved by their new model in which the universe has no beginning and no end.” (Read the full article
On the other hand, Alexander Vilenkin says the universe probably did have a beginning:
Some people believe we are in a new Enlightenment, with science making food plentiful and likely to make energy cheap enough to be unnoticeable in the next few decades as well. We share one other thing in common with the 18th century - solar activity.
Scientists have been counting sunspots
with small telescopes
since 1610 so it was quickly learned that the Sun’s activity increases every eleven years, according to the interval in the growth of the number of darker and colder spots in comparison with the rest of its surface. The more spots that appear, the more luminous the surrounding areas are, and our star shines brighter.
By Jillian Scudder, Postdoctoral Research Fellow in Astrophysics at University of Sussex
The universe is such a big place that it is easy to get baffled by the measurements that astronomers make. The size of UY Scuti, possibly one of the largest stars we have observed to date, is certainly baffling.
Last month, we got treated to three of Jupiter's moons - Europa, Callisto and Io - parading across the giant gas planet's banded face.
There are four Galilean satellites - named after the 17th century astronomer Galileo Galilei who discovered them among the first observations ever made with a telescope. They complete orbits around Jupiter ranging from two to seventeen days in duration and can commonly be seen transiting the face of Jupiter and casting shadows onto its layers of cloud. Seeing three of them transiting the face of Jupiter at the same time is less common, occurring only once or twice a decade in most cases. It last happened in 2013.
Red galaxies may be 'dying' young because they have prematurely ejected the gas they need to make new stars. There are two main types of galaxies; 'blue' galaxies that are still actively making new stars and 'red' galaxies that have stopped growing. Most galaxies transition slowly as they run out of raw materials needed for growth over billions of years but a pilot study looking at galaxies that die young has found some might shoot out this gas early on, causing them to redden and kick the bucket prematurely.
The Universe began about 13.8 billion years ago and evolved from an extremely hot, dense and uniform state to the rich and complex cosmos of galaxies, stars and planets we see today. The key source of information about that history is the Cosmic Microwave Background - CMB - the legacy of light emitted only 380 000 years after the Big Bang.
Astronomers have been searching searching for a particular signature of cosmic ‘inflation’ – a very brief accelerated expansion that, according to current theory, the Universe experienced when it was only the tiniest fraction of a second old. This signature would be seeded by gravitational waves, tiny perturbations in the fabric of space-time, that astronomers believe would have been generated during the inflationary phase.
Apparently, PLANCK says that BICEP2 did not detect gravitational waves. The signal was mostly intergalactic dust. That is my reading of a Google translate translation of an official Planck website.This is even more tentative and un-reviewed than the arXiv postings that often set off a big story. However, if this holds true it seems that BICEP2 did not indeed detect gravitational waves. This may have officially finally settled the matter of BICEP2.
To put it briefly, the habitability of a planet depends on it's distance from its star, the composition of its atmosphere, and the type of star its orbiting. If our own solar system is at all typical then planets like those known around Kepler 444 and reported in the paper arXiv:1501.06227 do not have atmosphere or have a Venus like atmosphere. If there is another Earth size planet to be found, father out, where it's a bit cooler it could be a home for life. If it did have life that life could, due to the age of the planet, have been in existence long before life on Earth.
That's still a bit of a mystery. Despite the name, it has nothing to do with comets. In 1976, several elongated comet-like objects were discovered in pictures taken with the UK Schmidt Telescope in Australia. Because of their appearance, and despite any connection with comets, they became known as cometary globules. They were all located in a huge patch of glowing gas called the Gum Nebula. They had dense, dark, dusty heads and long, faint tails, which were generally pointing away from the Vela supernova remnant located at the center of the Gum Nebula. Although these objects are relatively close by, it took astronomers a long time to find them as they glow very dimly and are therefore hard to detect.